This invention relates to a printing device for printing photographic data on a film in a camera. There is known a printing device having manually operable dials for day, month and year on the camera housing. In this type of printing device, however, as the data is set by manually operating the dial, there is a danger that the data setting is forgotten or erroneous data is set. To avoid the recording of erroneous data caused by data setting error, it is possible to print the data by using the display of time on a digital clock. However, the disadvantage which is encountered when the conventional type of digital clock is used with the printing device is that at least six digit readout members are necessary at a time of printing for day, month and year, thereby it being made difficult to incorporate such printing device in a camera of reduced size.
Accordingly, the display value of the digital clock is changing every second by counting the pulse with the frequency of 1 Hz. Naturally, the display value is changing even at the time of data printing. Therefore, the conventional device has been confronted with a danger that the data is double-exposed because the display value changes at the time of data printing. Accordingly the intensity of illumination of display of clock is constant, even at the time of data printing. On the other hand, the film speed value is depend on the film used at the photography. Therefore, it is necessary to change the intensity of illumination depend on the film speed at the time of data printing.
Accordingly, an object of the present invention is to provide a photographic data printing device which has overcome the above-mentioned drawbacks of the conventional printing device.
Another object of the present invention is to provide a data printing device using the digital clock, which holds the display value at the time of data printing to avoid the changing of the display value.
Still another object of the present invention is to provide a data printing device using the digital clock as the printing data device, which changes the intensity of illumination depend of the film speed value at the time of data printing to make the proper exposure.
Further object is to provide a printing device having a digital clock capable of displaying a time in second, minute and hour and a date in day, month and year simultaneously, while nevertheless being suited for use in a camera of reduced size.
A further object is to provide a printing device which produces a display of data only when the data are printed or monitored, thereby the consumption of electrical energy of a common battery of an exposure control apparatus is minimized.
A further object is to provide a printing device which enables data two or more times as much as the number of digit indicators used to be recorded in a single picture frame.
A furthermore object is to provide a printing device having a digital clock with setting means accessible from the outside of the camera housing in which the device is mounted to set desired values of data.